If she did ever did write a tell-all book, it would no doubt be a page turner. For a person known for her initial antipathy towards politics, Sonia Gandhi's rise as one of the most powerful woman in Indian politics has been nothing short of astonishing.

Born and raised in Italy, Sonia met Rajiv Gandhi while they were both studying in Cambridge. They got married and moved to India in 1968. Despite becoming a part of India's oldest and most powerful political dynasty, she remained on the periphery of politics for several years.

She is said to have been vehemently against Rajiv Gandhi joining the Congress party. Nigel Nugent, in his book Rajiv Gandhi - Son of a Dynasty, wrote of how she threatened her husband with divorce were he to join the party. Rajiv did, however, join the party after the assassination of his brother Sanjay in 1980 as the General Secretary. He became Prime Minister after the assassination of his mother Indira in 1984.

But Sonia's worst fears came true when Rajiv was assassinated in 1991. In the wake of her husband's death, she kept her distance from politics, declining several invitations by the Congress party to join them. She instead started the Rajiv Gandhi Foundation, a non-profit organisation, where she worked as its chairperson.

In the following years, she kept out of public life only to be seen at rare party functions.

Congress lost the general elections in 1996. The following year, Sonia joined the party. In several interviews, Sonia has talked about how circumstances had compelled her to enter politics.

She became the party President in 1998 and has held the position ever since and is the longest serving chairperson of the party.

Sonia fought her first Lok Sabha election in 1999 from Rae Bareli in Uttar Pradesh, the same constituency from where her mother-in-law had fought. Sonia was the lead campaigner for the party and won the seat to become the Leader of Opposition in the Lok Sabha.

In the 2004 Lok Sabha elections, Congress won 145 seats under her leadership. In their book Divided We Stand: India in a Time of Coalitions, Paranjoy Guha Thakurta and Shankar Raghuraman described her campaign style as reminiscent of Indira Gandhi, "wading into crowds despite the high level of security given to her."

The Congress then formed the government at the Centre with its allies as the United Progressive Alliance (UPA). The success of the party was attributed to her popularity among people and her successful campaigns in the run-up to the elections.

In light of the party's success, it was widely expected that she would become Prime Minister. The alliance had unanimously chosen her as their leader. But the BJP through the election race and after its loss raised objections to her Italian origins. Sonia surprised everyone by nominating Manmohan Singh for the prime ministerial post while she became the chairperson of the UPA.

She was named the third most powerful woman in the world by Forbes magazine in 2004.

In 2006, Sonia Gandhi was accused of holding an 'office of profit' as President of the National Advisory Council while being a Member of the Parliament. She resigned from the Lok Sabha but was re-elected from Rae Bareli.

She was on TIME magazine's list of 100 most influential people in the world in 2007 and 2008.

Under her leadership, the UPA came back to power in the 2009 elections with the Congress winning 206 seats in the Lok Sabha.

In an article in The Caravan in 2010, Ramachandra Guha wrote, "Sonia Gandhi is fanatically devoted to the memory of the two Congress prime ministers with whom she shared a home... In an August 2008 interview she gave the journalist Vir Sanghvi for Star Plus TV, Sonia Gandhi said she joined politics to honour the memory and sacrifice of the family members whose photographs graced the walls of her house. Passing, several times a day, the portraits of Nehru, Indira, and Rajiv, she could not refuse the invitation to lead the party they had once led."

Throughout Manmohan Singh's term as the Prime Minister, it was a widely held belief that he was merely a puppet through whom Sonia wielded power. This was often used by the NDA, sitting in the opposition in the parliament, to undermine the prime minister. Sanjay Baru, former aide of Manmohan Singh, in his book The Accidental Prime Minister quotes Singh as saying, "I have to accept that the party president is the centre of power."

Amidst charges of corruption in various scams such as the 2G scam, Congress suffered a massive defeat in the general elections of 2014 winning only 44 seats at the Lok Sabha. Sonia kept her seat, winning again from Rae Bareli.

The latest allegations by Natwar Singh may be a blow to the family as it struggles to stay relevant in the political landscape of the country, but has evoked a sharp reaction from the usually reticent Congress party president.